1. Technical Field
The present invention relates to a feeding structure for a sliding structural body in which a redundant length of a wire harness is absorbed by a link arm pivotally arranged on a protector base.
2. Background Art
FIG. 4 is a view showing a first configuration of the conventional feeding structure for a sliding structural body. Concerning this matter, refer to Patent Document 1.
This feeding structure adopts a feeding unit 51. The feeding unit 51 includes: a guide rail 53 horizontally arranged in the slide door 52 of an automobile; a slider 54 slidably engaged with the guide rail 53; and a pair of V-shaped links 55, 56, which can be freely opened and closed, and one end portion of the link 55 is connected to the slider 54 and the one end of the link 56 is connected to the guide rail 53.
The wire harness 57 is laid from the link 55 to the stationary portion 59 on the vehicle body side 58 through the slider 54 while the wire harness 57 is being bent into a substantial U-shape. One end of the wire harness 57 is connected to the wire harness 60 on the sliding door side by a connector and the other end of the wire harness 57 is connected to the wire harness 61 on the vehicle body side by a connector.
When the slide door 52 is opened and closed, the pair of links 55, 56 are opened and closed (extended and contracted). Therefore, while the slider 54 is relatively moving along the guide rail 53, it is located in the neighborhood of the stationary portion 59 on the vehicle body side at all times.
FIG. 5 is a view showing a second configuration of the conventional feeding structure for a sliding structural body. Concerning this matter, refer to Patent Document 2.
This feeding structure adopts a feeding unit 62 in which three long and short links 65 are connected between the slide door 63 and the vehicle body 64 of an automobile being capable of freely moving in the horizontal direction. The wire harness 66 is laid from the vehicle body 64 to the slide door 63 along the links 65.
When the slide door 63 is opened and closed, the links 65 are rotated in the opposing direction so as to cope with the movement of the slide door 63.
FIGS. 6A and 6B are views showing a third configuration of the conventional feeding structure for a sliding structural body. Concerning this matter, refer to Patent Document 3.
This feeding structure is composed as follows. A protector 72 made of synthetic resin is arranged in a slide door 71 of an automobile. A leaf spring 73 is arranged in the protector 72. A cap 74 made of synthetic resin is inserted and fixed to a forward end portion of the leaf spring 73. A wire harness 75 is supported by the cap 74 being pushed upward. One side of the wire harness 75 is laid on the slide door 71 side and the other side of the wire harness 75 is laid from the laterally long lower opening 76 of the protector 71 to a harness fixture 78 on a vehicle body 77 side. Hanging of the wire harness 75, which is caused when the slide door 71 is half opened, is prevented by a pushing force of the leaf spring 73. The protector 72 includes: a protector base (substituted by the reference numeral 72) and a protector cover 72a. 
FIG. 6A is a view showing a state in which the slide door 71 is near at the completely closed condition and FIG. 6B is a view showing a state in which the slide door 71 is near at the completely opened condition. When the slide door 71 is completely closed, the slide door 71 is tightly contacted with the vehicle body 77 side and the wire harness 75 is pulled backward at the fulcrum of the wire harness fixing fixture 78. When the slide door 71 is completely opened, while the wire harness 75 is being pulled forward at the fulcrum of the wire harness fixing fixture 78, a diameter of the wire harness 75 is reduced and the minimum radius of curvature of bend of the leaf spring 73 and the wire harness 75 is ensured by an annular wall 80 in the protector.
[Patent Document 1] JP-A-2001-122054 (FIG. 1)
[Patent Document 2] JP-A-2001-151042
[Patent Document 3] JP-A-2004-136735 (FIGS. 6 and 7)
However, in the first feeding structure of the related art shown in FIG. 4, the following problems may be encountered. Since the long guide rail 53 and the links 55, 56 are arranged, the number and the weight of parts are increased and the parts occupies a large space in the slide door 52. Further, the wire harness 57 is bent at a small diameter in a crossing portion in which the wire harness 57 crosses the slider portion 54 or the links 55, 56, which increases bending stress and deteriorates the durability of the wire harness. In the second feeding structure of the related art shown in FIG. 5, the following problems may be encountered. Simultaneously when the links 65 are rotated, the wire harness 66 is complicatedly bent at a small diameter, which deteriorates the durability of the wire harness 66.
In the third feeding structure of the related art shown in FIG. 6, the following problems may be encountered. It is necessary to provide a space in the protector 72, into which pull-up space 79 of the wire harness 75 is accommodated, and it is also necessary to provide a space in the protector 72, in which the annular wall 80 for regulating the minimum radius of curvature of bend of the leaf spring 73 is accommodated. Accordingly, dimensions of the protector 72 tend to increase and the protector 72 occupies a large area inside the slide door 71. Therefore, the degree of freedom of arranging the other auxiliary devices may be restricted and alternatively, it may become difficult to absorb a redundant length of the wire harness in case that the priority of using the space is given to the arrangement of the other auxiliary devices. Further, it becomes necessary to use a long wire harness (a long corrugated tube and electric wire) 75 to be laid in the large protector. Accordingly, in order to insert the electric wire into the corrugated tube, it takes much labor. Further, the manufacturing cost is raised and the weight is increased.
The above problems are caused in the same manner not only in the case where the feeding unit is applied to the slide door of an automobile but also in the case where the feeding unit is applied to the sliding structural body such as a slide door of a train or a slide door of a manufacturing apparatus or a detection apparatus. In these cases, the vehicle body and the apparatus body are referred to as stationary structural bodies.